A sub-acute toxicology study of CDB-2914, an antiprogestational drug, will be conducted prior to initial clinical investigation in women. This drug is intended as a post-coital contraceptive for women. The rhesus macaque has been chosen for this study because its reproductive physiology is closely related to humans. Twelve female rhesus will be randomly assigned to a high (100mg/kg weight), low (20mg/kg weight) and control (vehicle) dose group consisting of four per group respectively. CDB-2914 (high, low) suspended in aqueous suspending vehicle, and the vehicle (control) will be administered once per day by naso-gastric intubation for fourteen days. Blood will be collected daily for measurements of serum cortisol and drug levels. On day 15, all animals will be euthanized. All animals will have extensive hematology, blood chemistry and urinalysis at their respective necropsy date to determine any toxicologic effects of the drug. In addition, a gross necropsy will be conducted where representative organs and tissues will be fixed and stained for histopathology. All aspects of this study will be conducted following good lab practice (GLP) guidelines. All animals have been selected and have been assigned to their respective treatment groups. Treatments will commence in one week, with the first necropsies conducted in three weeks.